This is true of complete units in the sense that all parts of the refrigeration system and its controls are factory assembled and tested in a full state. There are four configuration:
Air-cooled, air-cooled
Air cooling system with water-cooled
Liquid-cooled, air-cooled
Liquid-cooled, water-cooled
Air cooling packages are limited by the amount of cooled air, which must be in the immediate vicinity of the machine. Examples of full-packaged air, refrigerators, air conditioners integral through the wall type and refrigerating units of the car.
Liquid cooling packs, often called " liquid", are stand-alone systems and can be either air-cooled or water-cooled (Numbers and 13.7 13.8). Because of the cooled water is very flexible and effective means of spreading the cooling in many types of construction range of refrigeration units available on the market is very big. They can be found compressors of all types: reciprocating, scroll, screw and centrifugal together with heat exchangers shell and tube type or lamellar heat exchangers.
Two refrigerant circuits are usually used because it gives you more features, flexibility, and offers some redundancy.
Air conditioning is the main application, but they are also used for process cooling, where the temperature range can be extended downward to use pickle instead of water. Water-cooled chillers are most commonly associated with cooling towers and this increases the chillers in the total thermodynamic efficiency compared air coolers, because heat transfer at or near ambient air wet bulb temperature, and higher, sometimes much higher, dry bulb thermometer. Many chillers are intended for operation in the reverse mode to ensure that the heating when it is required.
Hmm ratings, in accordance with EN14511, refer to the input and output of the chilled fluid temperature and ambient air condition (air-cooling) or cooling water inlet and outlet temperature (water cooled)...
Packaged Units 
